I'm on walkabout right now. I have pared down to a set of stuff that I can (and did) carry on to an airplane this week.
In these two bags I have
a cell phone
an ipod
a laptop
a camera
Supporting these, I have:
a charger for recharging the batteries of the camera
laptop charger
3 cards for the camera
a portable hard drive (for backing up said laptop)
And headphones:
two sets of earbuds and a splitter (for ipod, computer, language lessons, and sharing movies with friends)
cell phone headset
skype headset
Also:
a flashlight
a reading light
This is way too much technology to have on my person.